The present invention relates to a memory card such as Multimedia Card (registered trademark) or to an electronic device.
Multimedia Card (registered trademark) is a kind of a memory card which is embodying a simplified interface and reduced in size and weight. The Multimedia Card has seven connector terminals as external interface terminals. Since a serial interface has been adopted, a load on a host system can be reduced compared with an ATA (AT Attachment) interface adopted by a PC card or a hard disk, which renders the Multimedia Card usable in a simpler and easier system (See Non-Patent Document 1). There is also SD Card (registered trademark) which is another memory card derived from the standards of the Multimedia Card (registered trademark). The SD Card includes the external terminals of the Multimedia Card, while some types of the Multimedia Card include the command specifications of the SD Card. Of SD Card hosts (host apparatus primarily using the SD Card), there are some which not only use the Multimedia Card as the SD Card but also attempt to use the Multimedia Card as it is. In the present specification, the Multimedia Card (registered trademark), the SD Card (registered trademark), and an SD Card host will be termed simply as an M card, an S card, and an S card host hereinafter, respectively.
[Non-Patent Document 1]
Hiroto Okada, “Making Full Use of Multimedia Card,” Interface, CQ Publishing Co., Ltd., December, 1999, Vol. 25, No. 12, pp. 124–131.